The overall objective of the proposed research is the characterization of the kinetics of mineralization of calcium phosphates and the inorganic and organic components of teeth such as whole and carious enamel and dentine, predentine, plaque, calculus, and organic phases such as collagen and elastin. The highly reproducible constant composition procedure developed in our laboratory will be used over a range of ionic strength, concentration and pH typical of those in the mouth. It enables the mineralizing phases to be characterized and the rates of reaction to be measured with high precision. In parallel with these studies the solid mineralized phases will be characterized by electron microscopy, x-ray diffraction, specific surface area determination, microelectrophoresis and particle size analysis. The kinetics of remineralization of natural and artificial white spots on enamel surfaces will be investigated. In the latter case, the white spots will also be produced by a controlled dissolution method at constant undersaturation. The use of constant composition method in providing kinetic information for the development of possible methods for the remineralization of damaged enamel in the mouth will be of particular interest. Studies will also be made of the influence of added ions such as magnesium and strontium and growth inhibitors such as the phosphonates upon the nature of the calcium phosphate phase which precipitates.